Hi!
I'm currently playing Pompey by PBEM and i think i'm not far from winning (let's keep our figers crossed... against Caesar you can't never be sure... :blink

. We are on turn 20 something...
What i've done is more or less the same i did against the AI in my first play with Pompey: Sent Pompey east and try to avoid decisive engagements in Hispania with Caesar main forces while i gather armies on Africa and Macedonia to invade Sicily and Italy while Caesar is occupied in Hispania.
Caesar+veteran legions are nearly unstoppable, so better not to try to stop them at all. But keep them busy on Hispania as long as possible. There is room to maneuver in Hispania and with a little luck, avoid Caesar main forces and maybe even pounce on some isolated detachments from time to time. And always be a bother and try to take back strategic and Caesar objective towns once Caesar is gone from them.
Nothing new, just what Fabius did with Hannibal on the 2º Punic War
With a little luck in the Italy and Sicily invasions, you can get some NM advantage which will make combats against veteran legions more even. And of course, reduce Caesar income. When he come back to recover Italy, again try to avoid decisive engagements with him and recover Hispania while he's away. If he goes East, again try to steal the west in his back...
Pompey have a pretty good advantage on the sea, so he could use the fleets to move forces around and look for the weak spots.
Of course against an expert player all this is not easily done, but if your opponent don't act very aggressively with Caesar and his veterans and give you some time to recruit, build up and give some experience to your legions and leaders, you can make interesting things.
One Pompey trick i learned in some AAR i read around here is to try to recruit as much legions as possible in the first 2 or 3 turns in Italy and Sicily, before you lose those regions for good. Once Caesar take Italy and Sicily by event, all your forces (including units in training) will be safely transferred to Africa or Macedonia. Having those 3 or 4 extra legions from the start is a boon!
And i always try to save what i can from the Massilia forces before they are annihilated. Specially Ahenobarbus is a very interesting ** leader that can be saved with a little luck... He is the only 6 strategic rating available for Pompey.
Also Pompey can command foreign forces without penalties, so he can make good use of Galatians, Thracian, Numidian and Hispanic forces which are pretty cheap to get.
What i have never done is recruit much oriental legions. I found them very weak and worthless against Caesar veterans
I think this is a very nice scenario to play against a Caesar AI.
In PBEM, is not balanced at all, but if the less experienced player plays at Caesar it can be very interesting.
Regards